9 Aurigae

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9 Aurigae
Auriga constellation map.svg
Red circle.svg
Location of 9 Aurigae (circled)
Observation data
Epoch J2000        Equinox J2000
Constellation Auriga
Right ascension 05h 06m 40.62967s [1]
Declination +51° 35′ 51.8025″ [1]
Apparent magnitude  (V)4.93 - 5.03 [2]
Characteristics
Spectral type F2V [3]
U−B color index -0.03 [4]
B−V color index +0.34 [4]
Variable type γ Dor [5]
Astrometry
A
Radial velocity (Rv)−0.47±0.57 [6] km/s
Proper motion (μ)RA: −28.557 [6] mas/yr
Dec.: −171.822 [6] mas/yr
Parallax (π)37.0551±0.1371  mas [6]
Distance 88.0 ± 0.3  ly
(26.99 ± 0.10  pc)
B
Proper motion (μ)RA: −54.582 [7] mas/yr
Dec.: −156.009 [7] mas/yr
Parallax (π)37.0796±0.0631  mas [7]
Distance 88.0 ± 0.1  ly
(26.97 ± 0.05  pc)
C
Radial velocity (Rv)−1.88±0.17 [7] km/s
Proper motion (μ)RA: −32.386 [8] mas/yr
Dec.: −173.026 [8] mas/yr
Parallax (π)37.2115±0.0184  mas [8]
Distance 87.65 ± 0.04  ly
(26.87 ± 0.01  pc)
Orbit [9]
Period (P)391.7  d
Eccentricity (e)0.37
Semi-amplitude (K1)
(primary)		5.8 km/s
Details
A
Mass 1.97 [10]   M☉
Radius 1.56 [5]   R☉
Luminosity 6.042 [11]   L☉
Surface gravity (log g)4.07 [5]   cgs
Temperature 7,023 [5]   K
Metallicity [Fe/H]−0.12 [5]   dex
Rotational velocity (v sin i)21.0 [5]  km/s
B
Mass 0.49 [10]   M☉
Temperature 4,947 [12]   K
C
Mass 0.751 [13]   M☉
Radius 0.756 [13]   R☉
Luminosity0.162 [14]   L☉
Temperature 4,633 [14]   K
Other designations
V398 Aur, BD+51°1024, GJ 187.2, GJ 9174, HD 32537, HIP 23783, HR 1637, SAO 25019
Database references
SIMBAD 9 Aur A
9 Aur B
9 Aur C

9 Aurigae (9 Aur) is a star system in the constellation Auriga. It has an apparent magnitude of about 5, making it visible to the naked eye in many suburban skies. [15] Parallax estimates made by the Hipparcos spacecraft put it at about 86 light-years (26 parsecs) from the Solar System, [1] although individual Gaia Data Release 3 parallaxes place all three components at 88 light years.

A visual band light curve for 9 Aurigae, adapted from Krisciunas et al. (1993) 9AurLightCurve.png
A visual band light curve for 9 Aurigae, adapted from Krisciunas et al. (1993)

Kevin Krisciunas and Edward Francis Guinan discovered that the star is a variable star in 1990. [17] It is a well-studied Gamma Doradus variable, [5] and was one of the first stars to be so-classified. [18] This star type varies in luminosity due to non-radial pulsations. [18] Its apparent magnitude varies from 4.93 to 5.03 over a period of 1.25804 days. [2] For that reason it was given the variable star designation V398 Aurigae in 1995. [19] [2]

9 Aurigae is a multiple star system. The naked-eye component A is a single-lined spectroscopic binary. Only the signature of an F-type main sequence star can be seen in the spectrum, but the periodic doppler shift of the absorption lines demonstrates that there is a hidden companion in a 391.7-day orbit. The gravitational interaction of the two bodies produces variations in their respective motions, which is what creates the doppler shift. [9]

Four other companions to 9 Aurigae are listed in multiple star catalogs. [20] [21] The closest companion is a 12th-magnitude red dwarf 5″ away. [5] 90″ away is component C, a 9th-magnitude star with a spectral class of K5Ve, [22] which may also be a spectroscopic binary. [10] Further-separated still is a 14th-magnitude star, component D, proposed to be a more distant red giant, [23] although Gaia astrometry places it at a similar distance and with a similar proper motion. [24] The most widely-separated companion is component E, a distant unrelated star. [23] [25]

References

  1. 1 2 3 van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752 . Bibcode:2007A&A...474..653V. doi: 10.1051/0004-6361:20078357 . S2CID   18759600.
  2. 1 2 3 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  3. ↑ Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv: astro-ph/0603770 . Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID   119476992.
  4. 1 2 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  5. 1 2 3 4 5 6 7 8 Rachford, Brian L.; Foight, Dillon R. (2009). "Chromospheric Variability in Early F-Type Stars". The Astrophysical Journal. 698 (1): 786–802. arXiv: 0904.1620 . Bibcode:2009ApJ...698..786R. doi:10.1088/0004-637X/698/1/786. S2CID   693296.
  6. 1 2 3 4 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  7. 1 2 3 4 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  8. 1 2 3 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  9. 1 2 Abt, Helmut A. (1965). "The Frequency of Binaries among Normal A-Type Stars". The Astrophysical Journal Supplement Series. 11: 429. Bibcode:1965ApJS...11..429A. doi: 10.1086/190120 .
  10. 1 2 3 "HR 1637". Multiple Star Catalog. Archived from the original on 2020-09-16. Retrieved 2019-10-09.
  11. ↑ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  12. ↑ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  13. 1 2 Newton, Elisabeth R.; Irwin, Jonathan; Charbonneau, David; Berlind, Perry; Calkins, Michael L.; Mink, Jessica (2017). "The Hα Emission of Nearby M Dwarfs and its Relation to Stellar Rotation". The Astrophysical Journal. 834 (1): 85. arXiv: 1611.03509 . Bibcode:2017ApJ...834...85N. doi: 10.3847/1538-4357/834/1/85 . S2CID   55000202.
  14. 1 2 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  15. ↑ Bortle, John E. (February 2001). "The Bortle Dark-Sky Scale". Sky & Telescope . Sky Publishing Corporation. Retrieved 15 May 2017.
  16. ↑ Krisciunas, K.; Aspin, C.; Geballe, T. R.; Akazawa, H.; Claver, C. F.; Guinan, E. F.; Landis, H. J.; Luedeke, K. D.; Ohkura, N.; Ohshima, O.; Skillman, D. R. (August 1993). "The 9 Aurigae system". Monthly Notices of the Royal Astronomical Society. 263 (3): 781–788. arXiv: astro-ph/9304008 . Bibcode:1993MNRAS.263..781K. doi: 10.1093/mnras/263.3.781 .
  17. ↑ Krisciunas, K.; Guinan, E. (August 1990). "Unexplained Light Variations of the F0 V Star 9 Aurigae" (PDF). Information Bulletin on Variable Stars. 3511: 1–7. Bibcode:1990IBVS.3511....1K . Retrieved 1 December 2024.
  18. 1 2 Krisciunas, K.; Griffin, R. F.; Guinan, E. F.; Luedeke, K. D.; McCook, G. P. (1995). "9 Aurigae: Strong evidence for non-radial pulsations". Monthly Notices of the Royal Astronomical Society. 273 (3): 662. arXiv: astro-ph/9407094 . Bibcode:1995MNRAS.273..662K. doi: 10.1093/mnras/273.3.662 . S2CID   117588180.
  19. ↑ Kazarovets, E. V.; Samus, N. N. (January 1995). "The 72nd Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 4140: 1–28. Bibcode:1995IBVS.4140....1K . Retrieved 1 December 2024.
  20. ↑ Dommanget, J.; Nys, O. (1994). "Catalogue des composantes d'etoiles doubles et multiples (CCDM) premiere edition - Catalogue of the components of double and multiple stars (CCDM) first edition". Com. De l'Observ. Royal de Belgique. 115: 1. Bibcode:1994CoORB.115....1D.
  21. ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi: 10.1086/323920 .
  22. ↑ Alonso-Floriano, F. J.; Morales, J. C.; Caballero, J. A.; Montes, D.; Klutsch, A.; Mundt, R.; Cortés-Contreras, M.; Ribas, I.; Reiners, Ansgar; Amado, P. J.; Quirrenbach, A.; Jeffers, S. V. (2015). "CARMENES input catalogue of M dwarfs". Astronomy & Astrophysics. 577: A128. arXiv: 1502.07580 . Bibcode:2015A&A...577A.128A. doi:10.1051/0004-6361/201525803. S2CID   53135130.
  23. 1 2 Krisciunas, K.; Aspin, C.; Geballe, T. R.; Akazawa, H.; Claver, C. F.; Guinan, E. F.; Landis, H. J.; Luedeke, K. D.; Ohkura, N.; Ohshima, O.; Skillman, D. R. (1993). "The 9 Aurigae system". Monthly Notices of the Royal Astronomical Society. 263 (3): 781–788. arXiv: astro-ph/9304008 . Bibcode:1993MNRAS.263..781K. doi: 10.1093/mnras/263.3.781 . S2CID   18596475.
  24. ↑ Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR .
  25. ↑ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR .
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